Infrastructure health monitoring is an important issue in the transportation industry. For the case of cement-based structures in particular, detection of corrosion on reinforcing steel bars (rebar) is an ongoing problem for aging infrastructure. There have been a number of techniques that have shown promise in this area including microwave nondestructive testing (NDT) and thermography. Thermography is quite advantageous as it is an established method, and can be utilized for large inspection areas with intuitive results. Typical heat sources include induction heating and flash lamps, but these are not without drawbacks. Microwave nondestructive testing has also been successful at detecting corroded rebar, but at the cost of lengthy scan times. This paper presents an investigation into the potential of utilizing aspects of microwave NDT and thermography to create a hybrid NDT method, herein referred to as Active Microwave Thermography (AMT). AMT takes advantage of the electromagnetically lossy nature of corrosion byproducts and uses microwave energy to induce heat in the corrosion. Subsequently, the resultant heat profile is captured using an infrared camera. This paper presents initial simulations and measurements that highlight the potential of AMT to detect corroded rebar.

Meeting Name

40th Annual Review of Progress in Quantitative Nondestructive Evaluation, Incorporating the 10th International Conference on Barkhausen and Micro-Magnetics (2013: Jul. 21-26, Baltimore, MD)


Electrical and Computer Engineering

Second Department

Mechanical and Aerospace Engineering


Missouri University of Science and Technology. Center for Transportation Infrastructure and Safety


This work was partially funded by the Center for Transportation Infrastructure and Safety, a National University Transportation Center (NUTC) at Missouri S&T.

Keywords and Phrases

Corrosion Detection; Hybrid NDT Methodology; Microwave Nondestructive Testing; Reinforcing Steel Bars; Thermography; Bars (Metal); Byproducts; Infrastructure Health Monitoring; Transportation Industry; Thermography (Imaging); Thermography (Temperature Measurement)

International Standard Book Number (ISBN)


International Standard Serial Number (ISSN)


Document Type

Article - Conference proceedings

Document Version

Accepted Manuscript

File Type





© 2014 American Institute of Physics (AIP), All rights reserved.

Publication Date

01 Jul 2014